There has been a raft of commentaries recently about how countries like China and Russia are pursuing so-called anti-access/area-denial strategies aimed at driving the U.S. Navy from nearby seas. Some of the more colorful accounts describe a "line of death" in places such as the Western Pacific that U.S. aircraft carriers can't cross without being in imminent peril.

These fears are greatly exaggerated. U.S. aircraft carriers are extremely resilient, and among the most densely defended assets in the world. In addition, they are always on the move, meaning it is hard to find them when they are at sea and even harder to target them. In a few minutes, a nuclear-powered carrier can be many miles from where it was first spotted -- U.S. carriers can outrun most submarines -- and in a shooting war, U.S. forces would immediately move to blind hostile sensors capable of tracking our warships.

Since I already wrote a piece for The National Interest on August 11 about how unlikely it is that a forward-deployed carrier will be lost to hostile fire, I'd like to focus on another aspect in the recent "line of death" critiques. If a heavily defended and constantly moving carrier strike group is vulnerable to attack, what does that say about our land bases in places like the Western Pacific? They sure aren't moving, and without them the Air Force and Army would be hobbled in any war effort.

Take the example of Guam, where Washington has been building up military capabilities for some time. It's good to have a piece of sovereign U.S. territory for basing forces in the region, even if it is nearly 3,000 miles from China. But Beijing is well aware of military activities on Guam, and undoubtedly has contingency plans for disabling bases there. It wouldn't take much. The same is true of the handful of other major U.S. land bases in the region -- if Beijing decides to take them out, it won't be long before they're gone.

Now contrast that with the case of U.S. carrier strike groups. China's reconnaissance complex for monitoring nearby seas is fragile and incomplete. It may occasionally detect U.S. warships on the move, but there's little ability to maintain a track because the Western Pacific is a big place and satellites capable of providing targeting-quality information typically whiz across the earth's surface at thousands of miles per hour -- meaning they're soon gone over the horizon.

Hostile maritime reconnaissance aircraft, manned or unmanned, would be kept far away from the carriers by combat air patrols and the defensive systems on Aegis warships that always shadow the carriers. The advent of long-endurance drones complicates this challenge, but America's enemies have been coming up with improved area-denial capabilities for generations, and the U.S. Navy always develops suitable countermeasures. Aside from the usual kinetic responses, the service is continuously improving jamming and cyber capabilities for disabling enemy sensors and communications.

As military experts have repeatedly pointed out, there are many steps in the "kill chain" that leads from initial detection of U.S. forces in an area to destroying them. If naval forces can interfere with even one of those steps by shutting down a sensor, disrupting a command link, or intercepting weapons, the anti-access strategy collapses. This applies just as much to Russia or Iran as it does to China (although China always seems to be the preferred threat in current critiques).

So when Chief of Naval Operations Admiral John Richardson told National Interest Defense Editor Dave Majumdar last month that he expects U.S. aircraft carriers will successfully defeat the anti-access strategies of enemies in future conflicts, it was no surprise. The U.S. Navy has been successfully countering such strategies for over a century, and spends more than all its likely adversaries combined in staying abreast of the latest technology and tactics.

Unfortunately, the challenge of protecting U.S. forward bases from similar such attacks is much more difficult, because no matter how many times we disrupt the enemy's kill chain, he will still know where the targets are. They haven't moved. If he is determined, eventually his weapons will get through. Naval forces thus look intrinsically more survivable in regions where enemies are actively pursuing anti-access/area-denial strategies.

If you follow the "line of death" critiques to their logical conclusion, what they are really saying is that no U.S. forces except submarines and highly stealthy bombers will be able to survive in much of Eurasia as the century progresses. We better hope that's not true, because subs and bombers by themselves aren't going to win a war. At the very least though, critics ought to acknowledge that land bases within reach of well-equipped enemies are much more vulnerable to destruction than carrier strike groups continuously maneuvering hundreds of miles from shore.

Loren B. Thompson is Chief Operating Officer of the non-profit Lexington Institute and Chief Executive Officer of Source Associates, a for-profit consultancy. Prior to holding his present positions, he was Deputy Director of the Security Studies Program at Georgetown University and taught graduate-level courses in strategy, technology and media affairs at Georgetown. He has also taught at Harvard University’s Kennedy School of Government.